UE4 version of this scene: https://www.artstation.com/artwork/Gkly3
Recently, I did some test using Redshift. The metal/rough workflow in Redshift is very friendly to Real-time artists and I'm very happy with the result.
The mechanics of redshift is quite easy to understand. Self-illumination(include VDB emissions) easily reduces noise, but Optix denoiser performed optimistic on these issues.